[meteorite-list] Any comments on AGU Carolina Bays and YD Impact Papers ???

[Paul]

Did anyone on this list attend the 2007 AGU talks given 
on the extraterrestrial impact origin Carolina Bays and
the Younger Dryas (YD) event?

They include:

Kobres, R. et al. (2007) Formation of the Carolina 
Bays: ET Impact vs. Wind-and-Water Eos Trans. AGU,
88(23), Jt. Assem. Suppl., Abstract PP43A-10

http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=sm07&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=carolina%20bays&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c788%7c4554%7cFormation%20of%20the%20Carolina%20Bays:%20ET%20Impact%20vs.%20Wind-and-Water%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c5539757%205544311%20%2fdata2%2fepubs%2fwais%2fdata%2fsm07%2fsm07.txt

and 

Howard, G. A. et al (2007) Evidence for an 
Extraterrestrial Impact Origin of the Carolina Bays 
on the Atlantic Coast of North America Eos Trans. 
GU, 88(23), Jt. Assem. Suppl., Abstract PP42A-05 [8]

http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=sm07&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=carolina%20and%20bays&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c448%7c4520%7cEvidence%20for%20an%20Extraterrestrial%20Impact%20Origin%20of%20the%20Carolina%20Bays%20on%20the%20Atlantic%20Coast%20of%20North%20America%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2fsm07%2fsm07%7c5496677%205501197%20%2fdata2%2fepubs%2fwais%2fdata%2fsm07%2fsm07.txt

In part, the latter abstract read:

"We report results from a suite of cores taken from 
within a Bay, which we have named  "Howard Bay," located 
about 2 km north of the town of Duart in Bladen County, 
North Carolina. Located on the high western bluff of 
the Cape Fear River, the Bay is 2.7 km long, 1.6 km 
wide, and filled with about 9 meters of sediment with 
an encircling rim that is ~1-meter high. Analyses of 
seven cores along the long axis of Howard Bay reveal 
an assemblage of abundant magnetic grains, microspherules, 
carbon spherules, glass-like carbon, and iridium, 
typical of the YDB impact layer (12.9 ka) at many other 
sites across North America. The impact layer conforms 
to the basal contours of the basin, suggesting that the 
markers were deposited immediately or soon after the 
Bay formed. Further analyses of samples in complete 
core sequences reveal that, unlike typical, peat-rich 
Carolina Bays, Howard Bay essentially lacks peat, 
diatoms, pollen, or other organic materials, suggesting 
that this Bay never stored water for any sustained 
length of time. Furthermore, several trenches confirm 
that the deepest part of the Bay is filled with >6 m of 
cross-bedded eolian sand with no evidence of lacustrine 
sedimentation."

Does anyone know anything about the specific nature of
the "...abundant magnetic grains, microspherules, carbon 
spherules, glass-like carbon, and iridium...", which is
reported above? Where has "glass-like carbon" been
recognized as evidence of an impact?

Any observations or comments about these and related 
Younger Dryas talks given at the AGU would be appreciated.
I am curious if they either really found something or this
evidence is more of same unsubstantiated claims, i.e. the
playa lakes in the Texas panhandle are impact craters
and the Chippewa Basin of Lake Michigan is an impact 
crater, which appeared in Firestone's book.

Best Regards,

Paul


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